JUKI LK-1852 BARTACK STITCHING PROBLEM

[Novikov]

Hello everyone!

I know that there is not many of you who knows about technical problems of different types of machines for denim. 

So, few days ago i bought a JUKI LK 1852, it's a bartack stiching machine. Every thing goes well in till i tryed to advance timing by moving a disc under the machine.

Stitching is just ugly as F**** and when i tried to turn the disc back as before it didn't change any thing. 

If someone who has an idea of what it could be please tell me. 

I attach a photo with a result.

[Jorge Pantalones]

Funny, I just retimed a 42 stitch version of that machine last week.  I tune mine the same way I would tune any of our DL-5550's, etc. - or for that matter, just about any lockstitch machine, which is all the bar-tacker really is.  That is to say: raise ~2.5mm from bottom dead point & the hook should be meeting the scarf at the top of the eye.  Make sure the gap between the two is paper thin (recessed screws on left side of the bed arm just behind the bobbin area) and then, both before you start and after you finish, make sure you have a fresh needle and absolutely perfect thread line.  I find these machines are very sensitive to how they're threaded.

While you're in there, check the hook for any burrs both by feel and with a magnifying glass.

Try not to mess with the thread cutter; it's way more tedious and much less intuitive to fix.  A bad combination for sure.

Consider also, with 3 layers of denim and T-80 thread, your thread tension and needles (18's likely) are going to be very different from how that machine might normally be tuned.  Though timing should remain the same.

This seems to be a good, basic timing video.  It looks like he's working on a Singer but this same formula will get almost any lockstitch machine tuned well.  The timing info starts after the 8 minute mark:  

Also, this: